Chronic rhinosinusitis (CRS) is an inflammation of the nose and paranasal sinuses lasting for ≥12 weeks. Endoscopic sinus surgery (ESS) is considered during difficult to treat CRS. The minimally invasive technique focuses on the transition areas rather than on the ostia. The aim of this study was to evaluate symptoms, the number of acute sinusitis episodes, and satisfaction after ESS with either preservation or enlargement of the maxillary sinus ostium. Thirty patients with moderate nonpolypous CRS were enrolled. Uncinectomy only and additional middle meatal antrostomy were randomized for each side of each patient and performed single blindly. The symptoms questionnaires were filled at four time intervals. Significant symptom reduction was achieved independently of operation technique. The number of acute sinusitis episodes indicating the exacerbation rate decreased significantly at 9 and, on average, 68 months postoperatively. However, the exacerbation rate began to increase after 9 months postoperatively. Three revisions were performed on the side with uncinectomy only and one on the side with additional antrostomy. Most patients reported good satisfaction with both procedures. There was a trend for patients with asthma and/or job exposure to report insignificantly more frequently no satisfaction with surgery, especially with the uncinectomy-only procedure. Both procedures seem to be efficient in providing symptom relief and satisfaction. More studies are needed to evaluate if patients with risk factors benefit more from an ostium-enlarging procedure.